# Inch of water conversions

pressure conversions » inch of water conversionsThe online converter calculator on this page allows you to select the pressure/stress measurement unit you want to convert to starting from inches of water (inH2O). To make a conversion starting from a unit of pressure other than inch of water, simply click on the "Reset" button.

## What is inch of water?

### Definition:

The inch of water is a non-SI unit of pressure equal to about 249.082 pascals (1 inH2O = 249.082 Pa), the SI derived unit of pressure. It is also equal to 2.49082 hectopascals (hPa), or 0.249082 kilopascals (kPa), or about 0.002458248 atmospheres (atm), or 0.00249082 bars (bar), or 1.868268 millimeters of mercury (mmHg), or 0.036126 pounds per square inch (psi), or 5.2021857 pounds per square foot (psf) or 1.868268 torr (Torr).

The inches of water is the pressure applied by a column of water one inch high at 4 °C in a gravitational field.

The inch of water is a unit of pressure commonly used in the United States for measuring small pressure differences of air and other industrial gases.

*Notes:*

(i) The SI is an abbreviation for the International System of Units

(ii) The density of water at 4 °C is 0.999972 g/cm3 or approximately 1 g/cm3

(iii) According to the General Conference on Weight and Measures, the standard gravity is 9.80665 m/s² (or 32.1740 ft/s²)

### Symbol:

inH2O

### Plural:

inches of water

### Also known as:

inch water column (plural: inches water column), inch WC (plural: inches WC)

Below you can find a comprehensive list with conversions from inches of water to other (metric, imperial, or customary) pressure and stress measurement units.